A selection of choices of varying exposure, options to avoid avalanche paths

Limited chances to reduce exposure, avoidance not possible

Exposure time

None, or limited exposure crossing runouts only

Isolated exposure to start zones and tracks

Frequent exposure to start zones and tracks

Glaciation

None

Generally smooth with isolated bands of crevasses

Broken or steep sections of crevasses, icefalls or serac exposure

Using this scale

Any given piece of mountain terrain may have elements that will fit into multiple classes. Applying a terrain exposure rating involves considering all of the variables described above, with some default priorities:

Terrain that qualifies under an italicized descriptor automatically defaults into that or a higher terrain class.

Non-italicized descriptors carry less weight and will not trigger a default, but must be considered in combination with the other factors.